Advances in the use of organic and organomineral fertilizers in sustainable agricultural production

In view of the increasing demand for food due to population, high cost and scarcity of inorganic fertilizer due to government deregulation policy, and unavailability of high yielding crop varieties as planting materials; total reliance on inorganic fertilizer or organic materials alone as fertilizer may not be realistic. Complementary use of organic with inorganic fertilizer should be employed so as to sustain soil fertility management strategy for crop production. It is clear that the prospect of obtaining enough chemical fertilizer to meet the requirement of the teaming farming population in the tropic is remote. The current price of fertilizer calls for its economic utilization to meet specific requirements of crops. The current world-wide shortage of fertilizer and its anticipated adverse effect on food production has made many countries to explore the manorial value of organic manure to reduce pressure on the demand for mineral fertilizer as complementary use. This chapter is expected to discuss the use of inorganic fertilizer in combination with organic materials to be able to give the desired higher and sustainable crop yields than the sole use of inorganic fertilizer or animal manure. It is concluded that there are abundant organic wastes that could be used alone or combined with mineral fertilizers. The presence of organic manures in organomineral fertilizers ensures more residual effect, balanced nutrition and improvement in soil physicochemical properties. The use of the two sources has synergistic effect and reduces expenditure on scarce and expensive mineral fertilizers. It is a sustainable approach to ensuring high soil productivity and crop yield.